Pretreatment of Pomegranate and Red Beet Juices by Centrifugation Before Membrane Clarification: A Comparative Study

Abstract

Microfiltration is an appropriate process to clarify fruit juices; however, fouling is a limiting phenomenon against its industrialization. Centrifugation of red beet and pomegranate juices was performed at 2,000 and 4,000 rpm for 5 and 10 min before their membrane clarification. Effect of this pretreatment on permeate flux and fouling mechanisms were evaluated and changes in physicochemical properties of the juices were studied before and after centrifugation process. Pretreatment at 2,000 rpm showed positive effect on the membrane clarification of pomegranate juice and negative effect on the membrane treatment of red beet juice. Centrifugation at 4,000 rpm showed opposite effect compared with centrifugation at 2,000 rpm for both juices. Beneficial centrifugation pretreatment of pomegranate juice has not negative effect on its nutritional value. Practical Applications Fouling phenomenon is a limitation against industrialization of membrane clarification of fruit juices. Centrifugation is a pretreatment which can be used to decrease fouling; so, it can increase the performance of membrane processing. However, current work showed that centrifugation has not same effect on membrane clarification of different fruit juices. Centrifugation at 2,000 rpm is useful pretreatment for membrane clarification of pomegranate juice; but, this pretreatment at 4,000 rpm is appropriate method before membrane clarification of red beet juice.